1. Field of the Invention
The present invention relates to a disc rotor of a disc brake device configured to brake a wheel mounted on a vehicle, and a disc brake device equipped with a disc rotor. More particularly, the present invention relates to a disc rotor capable of improving heat radiation, and a disc brake device equipped with the disc rotor.
2. Description of the Related Art
Conventionally, a disc brake device or a drum brake device has been widely used to brake a wheel of, for example, a motorcycle. The disc brake device includes a disc-shaped disc rotor having flat surfaces and a caliper configured to seize the surfaces of the disc rotor to brake the disc rotor. The disc rotor is mounted coaxially on the wheel on a lateral side of the wheel. The disc rotor is mounted on a hub of the wheel such that the surfaces thereof are substantially perpendicular to a rotational axis of the disc rotor. The caliper is provided with pads having contact surfaces (seizing surfaces) configured to contact the disc rotor, and the contact surfaces of the pads are shaped to be flat to conform in shape to the contact surfaces (brake surfaces) of the disc rotor.
The disc rotor rotates along with the wheel. When a rider operates a brake lever, the caliper moves, and the pads of the caliper seize the disc rotor to thereby brake the wheel. In this operation, the pads and the disc rotor contact each other under a relatively large pressure, and therefore, friction heat is generated between the pads and the disc rotor. Typically, the disc brake device allows heat radiation better than that of the drum brake device, because the contact surface (brake surface) of the disc brake device is exposed to the outside, and hence to wind flowing from forward of the motorcycle.
However, in the conventional disc brake device, since the disc rotor has flat disc-shaped surfaces and is mounted coaxially on the wheel on the lateral side as described above, a contact area of the disc rotor which contacts the wind flowing from forward is relatively small. Accordingly, in recent years, there has been a need for improvement of heat radiation in the disc rotor.